Republican New Hampshire Gov. Chris Sununu has decided to endorse Nikki Haley for president, reports say, apparently settling on the former U.N. ambassador as the most viable alternative GOP candidate to Donald Trump. Sources told WMUR that Sununu will make it official at a town hall event alongside Haley in Manchester, New Hampshire, on Tuesday night. His office confirmed to The Washington Post that Sununu would be attending the event but did not say if he would be making the endorsement. “I look forward to joining Nikki at her town hall this evening—it’s going to be a lot of fun!” Sununu told the Post in a statement. His backing of the former South Carolina governor will doubtlessly come as a setback to Florida Gov. Ron DeSantis who, along with former New Jersey Gov. Chris Christie, had been mentioned by Sununu as someone he was considering supporting.